The present invention relates to lawn and garden equipment, in particular, the present invention relates to a lawn apparatus known as an aerator. Aerators are generally used to punch holes in soil or to remove cores from soil of approximately one half inch in diameter and three inches long to allow air and moisture and nutrients to enter the soil.
Several problems are present in existing aerators. The most common form of aerator has a reel or a tine assembly equipped with coring tubes or tines that are positioned on the reel or the tine assembly so they extend radially outwardly from the central shaft of the reel. The tines or coring tubes, in addition to providing aeration, provide propulsion for the aerator. As the assembly rotates, the tines rotate and punch into the ground to remove a core from the ground and also push the aerator forward. This arrangement provides excellent traction to propel the aerator along the lawn. However, it presents a substantial impediment to turning the device in a sharp turn, or to making a turn of sufficiently small radius to allow the operator of the aerator to make a second pass across the lawn immediately laterally adjacent to the previous pass. Typically, to accomplish a small radius turn, the user must expend substantial effort to force the aerator into position by lifting the front wheels or rear wheels of the aerator with the handle to remove the tines from the ground and to allow pivoting on one of the aerator wheels. Alternatively, if the tines are left in contact with the ground and allowed to propel the aerator, a turn having a large radiusxe2x80x94on the order of eight to ten feetxe2x80x94only can be accomplished. As aerators typically weigh between two and three hundred pounds, the repetitive lifting of the device by the operator can be exhausting to the operator. This can present a serious problem during the operation of a reasonably dangerous piece of equipment.
Yet another problem that exists with current aerators is the assembly of the plugging or coring tines on the reel or tine assembly of the aerator. Typically, aerators have coring tines which are sandwiched between parallel mounting plates. The tines are held in place by bolts passing through the mounting plates and through the tines. The mounting plates are then, typically, welded onto a shaft or a tube which is then mounted onto a shaft to comprise the coring tube reel. It is very difficult, if not impossible, for a user of the device to replace individual components of such a welded tine wheel assembly. In addition, the connection of the tine wheel assembly to the frame of the aerator makes it difficult for a user to remove the tine wheel assembly if it is possible to replace any parts of the tine wheel assembly.
Therefore, it would be an advantage, and is an object of the present invention to provide an aerator which allows the user to change the direction of travel of the aerator while reducing the need to manually lift the aerator tines out of contact with the ground.
Yet another object of the present invention is to provide an aerator that offers a much smaller turning radius and allows the user to re-position the aerator on the reverse line of travel adjacent to the previous line of travel with greatly reduced effort by the operator and without the need to lift and pivot the aerator to achieve pivoting on the front support or wheel of the aerator.
Another object of the present invention is to provide a tine assembly which is easily removable from the aerator and which allows the operator of the aerator to easily change the type of tine which is mounted on the aerator and the number of tines and the spacing between individual tine wheels to allow near complete user selection of the type of aeration process being achieved. It would be a great benefit to users and the small equipment rental industry if an aerator was provided with a easily removable tine wheel assembly which allowed the user to replace any damaged part of the tine wheel assembly.
Yet another object of the present invention is to provide an aerator having a differential in the front axis of the device to allow great maneuverability of the aerator as it is operated.
Another object of the present invention is to provide a front axle having a differential in combination with castered rear wheels to further improve the maneuverability of the aerator.
The present invention provides an aerator having a tine wheel assembly which is easily removable by an operator. Further, the present invention provides a tine wheel assembly which allows the operator to change the spacing between tine wheels and to change the number and type of tines included in each tine wheel and to individually replace tines which have become damaged. A differential is provided in the front axle to increase maneuverability and to allow the user to reduce the need for manually lifting the aerator by its handle in order to and to reduce the need to remove the tine wheels from contact with the ground during the maneuvering of the aerator. The present invention also provides a combination of a front axle differential with castered rear wheels to assist in maneuverability of the device. Further, the present invention allows the tine wheel assembly to be raised from contact with the earth while power is supplied to the differential of the front axle to assist in maneuverability of the present invention. Another feature of the present is a non-welded, easily removable tine wheel assembly which permits the user to easily replace components of the assembly.
The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.